A liquid crystal display is configured to have a liquid crystal held between transparent substrates of glass or the like. An alignment film is formed on each transparent substrate. The alignment film serves to align liquid crystal molecules in a predetermined direction, and is formed by applying a film of polyimide or the like and rubbing the film in one direction with a buff cloth. Rubbing is the most ordinary alignment scheme but with this technique it is difficult to provide uniform orientation while easily providing strong alignment restricting force.
An ion beam method is receiving attention as a new alignment technique in place of the rubbing method. The ion beam method provides alignment by accelerating ions of argon or the like with high voltage and irradiating an ion beam on a film of DLC (Diamond Like Carbon) or the like in an oblique direction. Contrary to the rubbing method, when using the ion beam method it is difficult to provide strong alignment restricting force while easily providing uniform orientation.
In case of forming an alignment film by the ion beam method, film deposition and alignment are separate processes (see Patent Documents 1 to 3 mentioned below). Therefore, two apparatuses, a film deposition apparatus and an alignment apparatus, are needed. This raises various problems, such as making the overall apparatus more expensive, the need for a wider apparatus installing space and the need for a rinsing process between the film deposition process and the alignment process.
For example, Japanese Unexamined Patent Publication (Kokai) No. 2003-222873 describes a method of executing an alignment process by forming a DLC film with magnetron sputtering, and then irradiating an argon ion beam on the DLC film while transferring a substrate. Japanese Unexamined Patent Publication (Kokai) No. 2006-047724 describes a method of executing an alignment process by irradiating an ion beam on a DLC film while transferring a substrate, but fails to give a detailed description of a film deposition process. In addition, an apparatus described in Patent Document 2 transfers a substrate from an upstream side to a downstream side, with masks provided on both the upstream and downstream sides. Japanese Unexamined Patent Publication (Kokai) No. 2006-284887 describes a method of executing an alignment process by forming a DLC film with plasma sputtering or CVD (Chemical Vapor Deposition) and then irradiating an ion beam on the DLC film while transferring a substrate.
Japanese Unexamined Patent Publication (Kokai) No. 2005-084145 (the 084145) describes a method of forming an alignment film in a single process of simultaneously executing a film deposition process and an alignment process by using ion beam sputtering. According to the method, an ion beam is irradiated on a target such as SiO2, so that sputtering particles sputtered from the target are irradiated on a substrate at an incidence angle θs. As a result, a columnar crystal is grown in a direction tilted by θs, thereby forming an alignment film. However, this method can form an alignment film only on a relatively small substrate. This is because with the positional relationship shown in the publication, a substrate if large, blocks an ion beam irradiated on a target from an ion source. In general, an ion beam and sputtering particles generated by the ion beam have certain spread irradiation ranges, which become wider because the distance between the ion source and the target is long according to the disclosed invention. Although paragraph 0036 of the 084145 document suggests movement of a substrate in such a way that the incidence angle becomes θs wile irradiating sputtering particles, it appears from the foregoing circumstance that an alignment film shall be formed only on a very small substrate.
Japanese Unexamined Patent Publication (Kokai) No. 2002-062532 describes a method of forming an alignment film in a single process of a simultaneously executing a film deposition process and alignment process by using ion beam sputtering. According to the method, a substrate is bombarded with an ion beam at a predetermined incidence angle, and at the same time, while a film is deposited on the substrate, the atomic structure of the film is aligned in a predetermined alignment direction, but no sputtering is performed.
Japanese Unexamined Patent Publication (Kokai) No. 2002-055348 describes a method of forming an alignment film in a single process of simultaneously executing a film deposition process and an alignment process by using magnetron sputtering. According to the method, a carbon film is deposited on a substrate with a magnetic field acting thereon, but no ion beam is used.